Stabilization



Patented Sept. 4, 1945 STABILIZATION Joseph S. Wallace, Hammond, Ind.,and Thomas E. Sharp Oil Company, Indiana Chicago, 11]., assignors toStandard Chicago, 111., a corporation of No Drawing. Application March4, 1943,

Serial No. 478.012

11 Claims.

This invention relates to sulfur bearing lubricants. More particularlyit relates to' odorstabilized lubricants comprising a sulfurizedhydrocarbon oil and to processes for preventing or eliminating theevolution of foul or toxic odors from such lubricants.

Experience has shown that excellent lubricants useful in metalfabricating operations such as cutting, drawing, stamping and the likeconsist of blends of sulfurized hydrocarbon oils. These lubricantscontain sulfur in loose chemical combination. true solution, or'both,the sulfur constill another object of this inventionis to P vent thedeterioration of sulfurized hydrocarbon oils. A further object of thisinvention is to protents varying in the range of about 1 to about 5% byweight, more or less. The normal viscosity range of these lubricants isabout 50 to about 300 seconds saybolt Universal at 100" F., althoughsulfurized lubricants of somewhat higher viscosity can be made and aresometimes used for specialized operations.

In spite of their excellent lubricating and cooling qualities in metalforming operations, sulfurized hydrocarbon oils suffer from the greatdisadvantage of odor development or evolution. Upon standing thesulfurized hydrocarbon lubricants evolve foul odors in the form ofvolatile sulfur compounds. The odor is due in large measure to hydrogensulfide and also appears to be due in part to the evolution of volatilemercaptans from the sulfurized lubricants. This odor is unpleasant andtoxic, constituting a highly undesirable attribute of the lubricantwhich renders it useless or. unsalable.

Odor evolution from lubricants containing sulfurlzed hydrocarbon oils isreadily detectable by mere olfactory examination. A much moresatisfactory method of examination, which yields visual and reproduciblerecords is as follows: A definite amount (usually 75 cc.) of the oil tobe 7 tested is added to 75 cc. of distilled water in a 500 cc. balloonflask. A paper which has been impregnated with a 20% aqueous solution ofhydrsted lead acetate and then dried is placed over the mouth of thefiask and held in place by means of a glass chimney. The flash is thenplaced in a boiling water bath for 30 minutes. At the end of this periodthe lead acetate paper is removed and examined for signs of blackening.This test has proved satisfactory for comparative evaluation ofdifferent samples.

It is an object of this invention to confer odor stability oncombinations of organic materials and sulfur which normally tend toevolve odor in the form of volatile sulfur compounds. Another object ofthis invention is to provide odor-stable lubricants comprisingsulfurised hydrocarbon oils.

vide processes to prevent the evolution of sulfurous vapors fromlubricants containing sulfur in loose chemical combination, physicalsolution or both. a

We have discovered that odor development in sulfur bearing hydrocarbonoils normally tending to evolve volatile sulfur compounds can beinhibited by adding thereto small amounts of an alkylolamine capable ofinhibiting such odor development. Suitable alkylolamines for thispurpose include 2-amino-2-methyl-l-propranol; 2- aminobutanol;2-amino-2-methyl-L3 propanediol; 2-amino-2-ethyl-l,3-propanediol;monoethanol amine; diethanolamine and triethanolamine. Ordinarily, weprefer to use triethanolamine, diethanolamine and2-amino-2-methyll-propanol. We particularly prefer to usetriethanolamine. Our odor inhibitors may generally be used inproportions varying from about 0.025 to about 1% by volume .ln thesulfurized lubricants. The specific proportion of odor inhibitor used inany case will be dependent on the method of preparation of thesulfurized lubricant, the nature of the hydrocarbon oils used, thesulfur-content of the libricant, the nature of the specific odorinhibitor chosen for use, its solubility inthe particular sulfurizedlubricant and the conditions under which the sulfurized lubricant istobe stored an used. Under specialized conditions more than 1% of thealkylolamine may be used.

The odor inhibitor may be added to the sulfurized lubricant at any stageof manufacture following sulfurization. It is preferable to incorporatethe inhibitor into the sulfurized lubricant immediately following thesulfurization'operation and in advance of the settlingoperation whichusually follows thereafter in the manufacture of such lubricants. Theodor inhibitor is not added to the reaction mixture undergoingsulfurization since the inhibitor is thereby converted to compoundswhich do. not display the desired odor inhibiting properties. The odorinhibitors of this invention may also be applied to sulfurizedlubricants which have already developed odor and will aid in fittingthem for further use.

In order to facilitate solution and/or dispersion of the odor. inhibitorin the sulfurized lubricant it is desirable that it be added underconditions of vigorous agitation, produced, for example, by mechanicalstirring or by the passage of gases such as dry steam or air through thecontents of thedissolution vessel. The odor inhibitor may i be added attemperatures as high as about 300' I". but it is preferred to usetemperatures below about 150 F. Sufficient quantities of the odorinhibitor may even be added at room temperature.

Specific applications of this invention to both 7 dark and light coloredcutting oils containing sulfurized hydrocarbon oils have provensingularly successful.

In order to illustrate this invention a specific embodiment as appliedto a light colored or transparent sulfurized cutting oil will bedescribed. Light colored sulfurized cutting oils are generally preparedby digesting hydrocarbon oils boiling in the lubricating oil boilingrange with flowers of sulfur at temperatures in the range of about 260to 320 F. at substantially atmospheric'pressure 1 for a period of timesufllcient to produce an oil containing about 1 to 3% of sulfur byweight. More or less sulfur will be added to the base oil during thesulfurization step, depending upon its I original sulfur content.Preferably, the finished oils will contain 2 to 3% of sulfur by weight.

1 The normal viscosity range of these cutting oils 1 is about 50 toabout'200 seconds Saybolt Universal at 100 F. although somewhat higherviscosity products are sometimes prepared.

Example 1 A blend of 73.5% of an oil which we shall designate as "A" and26.5% of an oil B" was seconds Baybolt Universalat 100 F. Oi1s"Cl'mamplez A blend of 77% of anoilwhlchvwe shall designate asfC. and 23%of an il .D'Kwas digested with 32 lbs. of sulfur per 1100 gallons atabout 340F. for 12 hours under substantially atmospheric pressure toyield a product containing 3.7% sulfur. The viscosity of the product was147 and D" had the following specifications:

'I'he hot reaction product was cooledto a temperature of 200 F. andblown with air for 45 7 minutes. At the end of this period thetemperature had reached 150. F. and 0.1% by volume of triethanolaminewas added'with thorough mechanical stirring. The productwas a darkcoldigested with 8 lbs. of sulfur per 100 gallons at 1 about 300 F. andsubstantially atmospheric pressure to yield a product containing 2.4%sulfur. 1 The viscosity of the product was 110 seconds Saybolt Universalat 100 F. Oils "A and 3" 1 had the following specifications:

After the sulfur clean-up had been effected the oil was allowed to coolto about 150 F. and 0.1% by volon n UB1,

Gravity, API 24.7 24.7

Viscosity- 100 F., seconds Saybolt Universal J 82 290 Viscosity at 210.F., seconds Saybolt Universe 36.6 Pour point, "F -25 Flash point, F 320Original sulfur, percent 0. 75-1.0

ume of triethanolamine and 0.2% by volume of 1 pine oilwere added withthorough mechanical stirring. The oil was further cooled and passed 1 totanks where uncombined sulfur and other inj soluble matter was separatedby sedimentation.

The product was a light colored cutting oil which proved extremelyresistantto odor development in storage and use; v

Our invention may also be applied with success to dark coloredsulfurized cutting oils. These oils differ from light colored oilsprincipally in sulfur content and color. In general they contain about 3to 5% by weight of sulfur in loose chemical combination and/or physicalsolution. Sulfurization is generally carried out at a somewhat highertemperature than that employed in the sulfurization step. used for thepreparation of light colored cutting oils. Usually sulfurization may beeffected in the temperature range 330 to 380 F. A specific example ofthe application of our invention to dark colored sulfurized cutting oilsis as follows:

bination of sulfur aridan organic material which normally tendsitdevolve volatile sulfur compounds.

It is apparent that 7 this invention suppiies a.

novel and useful means bywhich odor evolution in unstable sulfur bearinghydrocarbon ofls may be readilylnhibited. Further, it will beappreciated that this invention'provides novel compositions of matterwhich are highly useful as metal forming lubricants and at the same timedo not constitute a health hazard to the operators using the same.

We claim: l. A composition f matter comprising a culfurizedhydrocarbonoil containing substantially no corrosive halogen compound and being normally susceptible to odor development and an alkylolamine chosen fromthe group consisting of 2-amino-2-methyl-l-propanol; 2-aminobutanol;2-amino-2-methyl-L; 3-propanediol; 2-amino-2- ethyl-J, 3-propanediol;monoethanolamine, diethanolamine an'd triethanolamine, said alkyloiaminebeing present in sufficient amount sub '3-propanediol,Z-amino-Z-ethyl-l, 3-propanediol,

monoethanolainlne, dlethanolamlne and triathanolamine. s I

3. A compositional matter comprising a an] furized hydrocarbon oil,containing substantially no corrosive halogen compound and beingnormally susceptible ,to odor development and tri-' ethanolamine insufficient amount substantially to inhibit said odor development.

d hat our-invention isbr'oadly applicableto the-odor tabiliz'ati'on of4. A composition of matter comprising a sulfuriaed hydrocarbon oilcontaining substantially no corrosive halogen compound and beingnormally susceptible to odor development and diethanolamine insuiiicient amount: substantially to inhibit said odor'development. I

5. A composition oi matter comprising a suli'urized hydrocarbon oilcontaining substantially no corrosive halogen compound and beingnormally susceptible to odor development and 2-amlno-2-methyl-1-propanol in sumcient amount substantially to inhibitsaid odor development.

6. A metal fabricating lubricant comprising a sulfurized hydrocarbon oilcontaining substantially no corrosive halogencompound and being normallysusceptible to odor development, said lubricant having a viscosity inthe range of about 50 to about 300 seconds Baybolt Universal at 100 1".and a sulfur content of about 1 to about 5% and about 0.025 to about 1%of an alkylolamine and about 0.025 to about 1.0% of triethanolamine. 8.A process for. inhibiting odor evolution in a sulfurized hydrocarboncutting oil normally susceptible to odor evolution comprising adding tosaid cutting oil by means of vigorous agitation at a temperature belowabout 300 F. an albiolamine chosen from the groupconslsting of,

2-amino-2-methyl-l-propanol; V 2-aminobutanol; 2-amino-2-methyl-1,3-propanediol; 2-arnino-2- ethyl-l, 3-propanediol; monoethanolamine,diethanolamine and triethanolamine in quantity suiiicient substantiallyto inhibit said odor evolution.

9. A process for inhibiting odor evolution in a sulfurized cutting oilnormally susceptible to odor evolution comprising adding triethanolamineto said cutting oil by means otvigorous agitation at a temperature belowabout 300 1". I

10. A process for inhibiting odor. evolution in a suliurized cutting oilnormally susceptible to odor evolution comprising adding diethanolamineto said cutting oil by means-of vigorous agitation at a temperaturebelow about300f 1".

11. A process for inhibiting odor evolution in a suliurized cutting oilnormally susceptible to odor evolution comprising adding I-amino-Z-Ymethyl-l-propanol to said cutting .oil by means 01 vigorous agitation ata below about 300 1".

JOSEPH} a warmers. mourns a sump.

